"You might be surprised to learn just how long treated lumber can remain intact and
untouched by rot, fungi, and insects."
Treated lumber is a popular building material that plays a key role in the construction of many structures in the
Pacific Northwest. Our good friend Dennis McWhirter is an expert on pressure-treated wood, with nearly three
decades of experience in the industry. In this series, Dennis provides answers to some common questions, and
reminds us why treating lumber is one of the best things we can do to help preserve our greatest renewable
resource.
The age-old question with treated lumber is: How long will it last? In today’s video, Dennis sheds light on that
question. Here’s a recap of our conversation:
How long will pressure-treated lumber last outside?
Back in 1961, two wood scientists planted treated-lumber posts in the ground of southern Mississippi. Sixty years
later, most of those posts are still there—no rot, no fungi, no termites. Their experiment set the official
statistical lifespan of treated lumber that the industry refers to today: over 60 years.
Of course, it’s important to consider the factors that can affect the lifespan and performance of
pressure-treated lumber: drainage, maintenance, proper application, and sun exposure.
How long is the warranty period for pressure-treated lumber?
All of our treated lumber products come with a lifetime warranty. The warranty will stay intact so long as the
specific product is used as intended and any field cuts are sealed with end cut solution. Other suppliers may
have different warranty periods or stipulations depending on the application of the lumber.
Typically, the warranty is to the original owner of the pressure-treated lumber—unless you’re working with a
contractor. In that case, the contractor can transfer the warranty over to the homeowner after construction is
done.
Dennis is a wellspring of information on treated lumber, and we hope that sharing his knowledge will help you
decide if pressure-treated lumber is right for your project. To learn more about pressure-treated lumber, check
out how to maintain the
lifetime warranty of pressure-treated lumber and this article on the
difference between professional- and premium-grade lumber.